Screening apparatus.



G. H. FRASER.

SCREENING APPARATUS.

APPLICATION FILED DEC-18.1907. RENEWED MAY 4. 1916.

Patented Oct. 24., 1916.

5 SHEETS-SHEET 1.

G. H. FRASER. SCREENING APPARATUS.

APPLICATJON FILED use. 18. 1901. RENEWED MAY 4.1916.

,8'75. Patented Oct. 24,1916.

5 SHEETS-SHEET 2.

F/GB.

INVENTOR WITNESSES: mfn' a W W A 1 W6.rgaman M Patented Oct. 24, 1916.

5 SHEETS-SHEET 3.

INVENTOR wxq.

G. H. FRASER.

SCREENING APPARATUS. APPLICATION FILED DEC. 18. 1907.

RENEWED MAY 4.1916- mmmaw RENEWED MAY 4.1916.

G. H. FRASER.

SCREENING APPARATUS. APPLICATION FILED 050.18.1907.

FIG. 4.

WITNESSES G. H. FRASER.

SCREENING APPARATUS. APPLICATION FILED DEC. 18. I907- RENEWED MAY4.1916.

LQfiQfiTffi. Patented Oct. 24,1916.

5 SHEETS-SHEET5.

'INVENTOR WlTNESSES:

GEORGE HOLT FRASER, OF NEW YORK, N. Y.

' SCREENING APPARATUS.

reoasva Specification of Letters Patent.

Application filed December 18, 1907, Serial No. 407,020. Renewed May 4,1916. Serial No. 95.496.

To all whom it may concern: 7

Be it known that I, Gnonen HOLT FRAsER, a citizen of the United States,residing in the borough of- Brooklyn, county of Kings, city and State ofNew York, have invented certain new and useful Improvements in ScreeningApparatus, of which thefollowing is a specification.

This invention relates'to apparatus for screening, sizing or separatingfinely divided materials, and aims to provide improve provides certainimprovements in the construction, arrangement and operation ofmechanical screening apparatus, and combines with such apparatus fluidcurrent separating devices.

It also provides various other features of improvement, allofowhich'will be hereinafter more fully set forth with reference to theaccompanying drawings, in which-- Figure 1 is a side elevation of thepreferred form ofthis invention; Fig. 2 1s a transverse section thereof;.Fig. 3 1s a plan view thereof; Fig. 4 is a front elevation thereof;Fig. 5 is a rear elevation thereof; and Fig. 6 is a longitudinal sectioncut on the-line 66 in Fig. 2. Figs. 7 and 8 are enlarged fragmentarydetail views of the wall S. Figs. 9 and 10 showmodifications.

Referring to the drawings, A A are the side frames of the screen casing,B is the inclined front-thereof, C is the inclined back thereof, and Dis the distributor at the top thereof. I J I E are the screen memberswithin the casing, F, .G, H and I are'discharge outlets, and J is thefeed hopper.

According to thisfinvention the sides A are each a single member orcasting pivotally mounted at the lower end on feet K, I

and supported bylegs L so as to be adjustable as to angular1ty,-thesecastings each be-' ing formed with bearing sockets for the usualrevolving conveyer M and vibrators N. The bottom wall C is of greatersteepness than the screen E, and is removably conneoted to give accessbeneath the screen. The top B is open or foraminous. The

screens E are movable, being separate members carried in aspring-mounted frame adustably supported by springs O and limited inupward movement by knocking stops P.

The distributer D has adjustable feed boards Q at each'side of theconveyer, constituting'a trough-for the latter, through which trough theniatei-"i'al'is worked as it is being distributed over the edge of oneor the other of the feed boards according to which direction theconveyer M is rotated. Beneath the conveyer are inclined deflectors R-Which receive the material'from the ends of-the boards and deliver itontothe screen.

Beneatli gthe screen is a foraminous wall S onto wvhicli falls the finematerial which passes through the screen. This wall is preferablycomposed of a great number of steps, plates or slats overlapping oneanother, and spaced apart sufficiently to form narrow openings betweentheir overlapping edges, so that thesurface of the wall is substantiallya serrated or stepped surface with backwardly and upwardly opening slotsbeneath each of the steps. The slats composing the steps are adjustablein inclination both together and independently to vary the width of 'theopenings between them (see Fig. 7 Their steepness is such that materialwill rapidly flow down from one to the next. The wall formed by themultiplicity of slats is adjustable to vary its steepness independentlyof the screen and the casing.

The wall S is spaced apart from and above the bottom C and is adjustablerelatively thereto, thus forming a conduit or passage T beneath thewallS which can be varied to adjust fiowback of this wall.

Preferably the walls is spring mounted and vibrated to agitate itssurface and eX- v pedite flow of material down it. As shown, it ismounted on rods U supported by ad:

justable springs V, on which rods-the springs O for the screen frame arealso adjustably mounted.

Vibration of the screens E and wall S is effected in anyway, as by thecam wheels W which are carried by rods adjustably screwed to the screenframe and ride on the shafts or wheels. N.

When a single'separation of sizes suificiently large to permitmechanicalscreening is desired, the material passing through the screens E willflow into one outlet G, and the coarse material passing over the screenwill flow into the other outlet F. In such case the bottom wall S willby its vibration faciltate the speedy downflow of the fine material.When, however, it is desired to make one or more additional separations,my invention provides for this by employing a fluid current, air if dryseparation, and water if wet separation, is desired. To this end Ipreferably inclose the screen apparatus as thus far described within acompartment or chamber X, in which the whole is immersed in water if wetseparation is desired, or is inclosed in air or other gas if dryseparation is necessary, and within this chamber I provide means forcirculating the separating medium preferably in reverse direction to theflow of the solid material. As illustrated, a rotary blower or pump isused, and is connected to draw the air downwardly through the screens Eand upwardly beneath these screens and through the interstices of thewall S, and then through the conduit T back of this wall, preferablynpwardly to a return conduit Y, which communicates with a settlingchamber or centrifugal collector Z, which discharges its fines into theoutlet 1 and exhausts into a second settling chamber a, whichcommunicates through a burlap or other sieve 7) into an exhaust chamber0, which latter communicates with the suction of the pump (Z, whichlatter discharges into a second centrifugal collector or settlingchamber 0 above the front of the screen, which collector e dischargesits settlings into the outlet I and exhausts its air into thecon'ipartment 7 above the screen, so that the air thus cleared of finesis discharged at the top of'the screen through the front B and. throughthe forward inlet 9. The effect of this is to create a suction at theback of the screen, clean the air, and return it to the front of thescreen, thus forming an endless circuit of inelosed air or other fluidin which the screening and separating operations are conducted, the samefluid being used over and over, and the floating fines being collectedat various stages beyond the screen, and at both the suction anddischarge sides of the pump.

The current will be adjusted to give the proper speed of flow throughthe interstices in the wall S, and these will be regulated as to width,length and inclination to best suit them to the work. The currentinduced through these interstices immediately back of the fallingmaterial will be sullicicnt to catch and lift the floating linesbackwardly and upwardly through the cracks, but as the cracks are passedthe speed of the current will instantly diminish owing to the greaterarea of the conduit T, so that the greater portion of the fines carriedthrough the wall. S will be deposited on the inclined bottom wall,flowing down the conduit T to the outlet H. Only such material as isline enough to float upward with the reduced current will pass over thetop of the bottom all C and down through the converging conduit Y to thecentrifugal separator Z. The well known centrifugal action of this typeof separator will be recognized as sullicient to remove most of theremaining floating material from the fluid current, so that the exhaustfrom the separator Z will contain very little fine material. The suctionto the fan will be in part protected from receiving fine material by thesieve Z), which may be burlap or other suitable bolting material, whichwill keep itself clean by the fact that it is loose and free to flap upand down with variations in the suction. The second centrifugalseparator 6 should entirely clear the current of all fine material, andthus the return flow to the top and front of the. screen should bepractically clean.

The outlets F, G, H and I will be. suitably sealed to prevent undueoutflow of the fluid medium, as by mechanism causing the dischargedmaterlal from each to seal the outlet opening until' removed by someautomatic means, such as an elevator It, 2', j or Z5, opposite eachoutlet lifting away only enough of the material to leave the outletcontinually closed, and when wet separation is employed the legs of eachelevator will be as high at least as the height of the liquid levelwithin the compartment X. The casings of, these elevators seal theseoutlets in the construction shown.

It will be seen that this invention provides for the distribution of thematerial to be sized in a thin layer over an extensive inclinedforaminous surface, in a compartment in which the material is surroundedby a fluid medium circulating at a sufliciently moderate speed not tointerfere with the coarser separations incident to gravitation, and notto interfere with the proper gravity flow of the coarser gradings totheir respective outlets; and that it provides for successive droppingof the material from stage to stage across a multiplicity of greatlyaccelerated currents of fluid, then for the settling of certain gradesby gravitation, and then for clarifying the fluid by both centrifugaland mechanical action.

It will be understood that these means are broadly applicable, and thatthe invention is not limited to the particular details of construction,arrangement and operation set forth as constituting its preferred form,since it can be availed of in whole or in part according to suchadaptations as circumstances or the judgment of those skilled in the artmay dictate vithout departing from -the spirit of the invention.

Thecam wheels W are adjustably carried by thescreen frame by rods whichmay be screwed into the screen frame and pass through the front, and bescrewed onto the roller bearings.

Although the front inlet 9 acts as a jet opening for an inwardly andupwardly flowing current, it may be desirable to supplement this by anumber of transverse pipes m directly above the wall S, each having aslot or jet-opening for directing a current of air toward the wall.These pipes maybe con trolled by valves n, and fed by a branch main 0.

If desired the upward current back of the wall S may be dischargeddirectly into the chamber a by turning down the gate Z, so that thecurrent will flow downwardly back of the chamber 0 and flow into thechamber a.

he sieve may be cleaned by pivoted cross rods ;0 which are lifted byvariations in the suction, and depressed by a spring q, or otherwiseoperated to move or crease the burlap, which will tend to release anymaterial collecting on it.

When the discharge is made directly nto the chamber a, the duct Y'may beomitted, and an inclined wall may subdivide the chamber a, and twocentrifugal apertures may be placed beneath this chamber with theirinlets opening opposite and adjacent to each other, and their outletsconnected to the suction of the fan; In this way their inlets willminimize the current between them and create a settling space under theinclined wall The apparatus may be driven by a belt r from a remotesource of power, and the drive may be reversible to cause the conveyerofthe distributer to operate in whichever direction is most convenient.When it is desired the current back of the wall S may descend instead ofascend.

This invention provides an improved process of sizing and separatingmaterial consisting in first disposing the unsiz'ed mass in a thin film,then subdividing it into superposed layers of difierent grades, thenflowing it by gravity transversely and-reversely of a fluid current, andthus washing the coarser grades from thefiner grades, and then sizingthe finer grades by centrifugal action and by sedimentation and bybolting.

It will be understood that these improvements can be utilized accordingto any suitable means which may be adapted to these improvements, andthat this improved apparatus may be used in whole or in part accordingto any known methods of treatment,

and that neither is limited to the particular details set forth asconstituting the preferred form thereof.

One improvement is illustrated in Fig. 9, in which the wall S isarranged as a foraminous cylinder with internal edges, consisting of anumber of angle irons fastened to cylindrical heads, the flanges of theangles being turned in to form internal steps which lift the material tobe screened, while the fines escape at the cracks between the angles orby an end exit. A fluid current may be drawn through the cylinder, orthe current may go through the cracks either inwardly or outwardly toremove the fines as the mass is being revolved in the cylinder.

Fig. 10 shows a form in which the cylinder is made of T-irons the edgesbeing joined, and the projections being inward so as to form under-cutpockets within the cylinder, in which pebbles will lodge, thus makin awear face for the material being revolved therein. In this case thecurrent will pass axially through theeylinder.

WVhile I have herein shown and described the feeder and distributer setforth,the same is not claimed in this application, being the subjectmatter of claims in my application Serial No. 82,750 of 1915 filed March7 1916 and in my application Serial No. 33,464 of 1915 filed June 11,1915, and in my application Serial No. 33,465 of 1915 filed June11,1915.

I claim as my invention 1. In combination, a removable adjustablevibrating screen inclined at an angle of approximately 45 degrees, aninclined floor or bottom below said screen and spaced apart therefrom,means for adjusting said screen to vary its inclination relatively tosaid floor or bottom, and downwardly acting vibrating means forvibrating said screen downwardly.

2. In combination, one or more removable vibrating scr'eens inclined atan angle of approximately 45 degrees and adjustable to vary suchinclination, a casing adjustably inclosing said screen or screens, saidcasing comprising an inclined floor or bottom beneath saidscreen orscreens, adjusting means for adjusting the lower part of said screen orscreens relatively to said floor or bottom to vary the inclination ofsaid screen or screens,.adjustable downwardly acting jarring means forvibrating said screen or screens, and means yieldingly supporting saidscreen or screens in said casing.

3. In combination, a plurality of inclined vibrating screens disposedone above another, means for vibrating said screens, and

means adjustably connecting them together for controlling their relativeinclination.

4;. In combination, an inclined removable vibrating screen, a casing forsaid screen,

means supporting said screen from said casing, adjustable bars or postsengaging said screen, vibrating mechanism acting on said bars or postsfor vibrating said screen, and a revolving part operating saidmechanism.

In combination, a removaliilymounted vibrating screen inclined at anangle of approximately degrees, a casing removably inclosingsaid screenand comprising an inclined floor or bottom beneath said screen and aninclined top portion above said screen, springs yieldingly supportingsaid screen and acting to press it upwardly in said casing, movable stopmembers or rods above said screen acting downwardly against the latterand upwardly toward said inclined top portion of said casing forpositioning said screen and resisting said upward pressure by saidsprings, and downwardly acting jarring means above and for vibratingsaid screen.

Copies of this patent may be obtained for five cents each, by addressingthe 6. In combination, a removably mounted screen inclined at an angleof approximately 45 degrees, a casing removably inclosing said screenand comprising an inclined floor or bottom beneath said screen and aninclined top portion thereover, springs for pressing said screenupwardly in said casing, means Commissioner of Patents.

Washington, D. C.

